The invention relates to an apparatus for the alignment of bottles or the like such as might be required for placing labels on the bottles.
Various kinds of apparatus for the alignment of bottles are already known. They serve generally the purpose of bringing the markings present on the bottles as exactly as possible into a determined angular position, to fix the bottles in this position and then to transfer them to a subsequent treatment station where the bottles are provided, for example, at determined locations with labels.
In one known apparatus for the alignment of bottles, the bottles are set in rotation by means of a friction surface arranged stationarily on a rotating transporting radially extending unit and acting directly on the bottle periphery, until upon recognition of a marking on the bottle by means of a scanning device, spring-tensioned clamping jaws are pressed onto the bottle (German Laid Open Specification No. 17 61 150). The aligned bottle slides then until it is discharged from the transporting radial unit to the stationary friction surface. It is unfavorable in this connection, that the friction surface is still effective, after the braking or retarding of a bottle, to turn the bottle against the braking force of the clamping jaws. Under some operating conditions, this may result in the bottle already retarded or braked being rotated further a determined angular amount, and accordingly higher than desired deviations from the desired end position of the markings occur. A further disadvantage is that the amount of rotation of the individual bottles is a variable dependent upon the rate of rotation of the transporting radial unit. This leads to differing track alignment angles within the forced retardation time between the operation of the scanning device and the complete locking of a bottle when the apparatus is operated with different outputs and, hence, leads to some deviation from the desired end position of the markings.
In another known apparatus for the alignment of bottles with a rotating transporting radial unit, there are connected between the stationary friction surface and the bottles movable friction rolls coupled with the clamping jaws, said friction rolls being raised upon a closure of the clamping jaws from the friction surface and/or the bottles (German Laid Open Specification No. 27 40 220). In this manner, no after-rotation of the bottles is any longer possible after the locking. Unfavorable, however, as before is the different lagging angle within the retardation time up to complete locking of the bottles upon operation with different machine speeds or outputs.
In the case of a known apparatus of the type described first above, each friction element is a friction roll which is seated on the radially inwardly disposed side of the pocket or bottle receiving recess of the transporting radial unit and is connected directly with an individual braking motor or through a coupling-braking unit with a common operating motor for all friction rolls (German Laid Open Specification No. 25 17 443). By means of a guide member disposed stationarily on the periphery of the transporting radial unit, which former extends from the inlet- to the outlet-area, the bottles are held in the receivers of the transporting radial unit and pressed onto the elastic friction rolls. The guide member may indeed consist of material low in friction. However, it still exerts on the bottles sliding on it (on account of the required pressure force for the friction rolls after the locking of the bottle rotation and--upon operation with different outputs) a determined torsional or twisting moment, which on account of the relatively low braking effect of the friction rolls may lead to undesired rotation of the bottles. Particularly with high machine speeds or outputs, this torsional or twisting moment is not unappreciable, as here the pressure force on the guide member is still augmented by the centrifugal force taking effect on the bottles. In addition, on account of the unavoidable deviations in the dimensions and the form of the bottles, different surface-character of the bottles which are in contact with one another, unequal wear of the guide member and the friction rolls unpredictable friction conditions occur in practice, so the accuracy of alignment attainable with the known apparatus is usually not sufficient. The theoretical possibility of attaining through a corresponding disposition of the operating motor a speed of rotation of the bottles independent of the machine speed and therewith a constant lagging angle is not obtainable in practice.